The speaker rejects an ex-partner who has returned with friendly calls and apologies. She says she has already cried, made her decision, and moved on, so his attempts to reconnect will not change her mind. The emotion shifts from recalling hurt and betrayal to projecting confidence and firm distance. Her repeated, blunt refusal sounds defiant, though it may also be a way of asserting strength after a painful breakup.
“Cut you off” means ending contact, not physically cutting someone. “You made your bed, sleep in it” is an idiom: people must accept the consequences of their own choices. The image of the ex “begging on your knees” suggests desperation and a reversal of power, while “all in the past” presents the relationship as something she has put behind her.
The lyrics make the speaker’s boundary clear, but her repeated insistence that she does not care can be read in more than one way. It may express genuine indifference, or it may emphasize how hard she is working to show that she is no longer vulnerable. The song does not settle that question; it focuses instead on her decision not to return to the relationship.